Pancreatic cancer is the fifth leading cause of cancer death in the United States. Since there are no effective treatments for the overwhelming majority of patients with this terrible disease, pancreatic cancer is one of the few diseases where the incidence equals mortality. A new approach for the treatment of these patients is urgently needed. We have developed a cancer-specific cytotoxic gene therapy for human pancreatic cancer that appears to be successful in a SCID mouse model. The exciting new finding central to this proposal is that the rat insulin promoter is activated in pancreatic cancer, thus permitting tumor-specific activation of suicide genes. Our hypothesis is that human pancreatic cancer cells can be selectively ablated using a rat insulin promoter-thymidine kinase construct and a liposomal gene delivery system followed by ganciclovir treatment. The specific aims of the proposal have been designed to test the hypothesis: Specific Aim I: todetermine whether a) PDX-1, BETA-2, GATA-4 and/or E47 transcription factors regulate expression of rat insulin promoter in human pancreatic cancer cell lines, b) these transcription factors are present in resected human pancreatic cancer and metastases, and c) the cytotoxic effect of rat insulin promoter-thymidine kinase and ganciclovir invitrocan be enhanced by cotransfection of human pancreatic cancer cell lines with PDX-1, BETA2, GATA4, or E47. Specific Aim II: to determine whether the rat insulin promoter-thymidine kinase and ganciclovir can be used to ablate human pancreatic cancer cells invivoin SCID mice via a) iv versus ip liposomal versus adenoviral delivery systems b) repeated rat insulin promoter thymidine kinase gene delivery and prolonged ganciclovir treatment, c) escalating doses of rat insulin promoter thymidine kinase and d) to determine whether the cytotoxic effect of rat insulin promoter-thymidine kinase and ganciclovir invivocan be enhanced by invitroor invivocotransfection of human pancreatic cancer cell lines with PDX-1, BETA2, GATA4, or E47. Specific Aim III: to determine whether a)rat insulin promoter-thymidine kinase and ganciclovir treatment will affect isolated mouse and human islets invitrousing liposomal versus adenoviral gene delivery systems and b) invivoliposomal versus adenoviral rat insulin promoter-thymidine kinase and ganciclovir will affect native mouse islet and/or transplanted human islet morphology, insulin secretion and glucose regulation in SCID mice. The purposes of this proposal are to 1) acquire a greater understanding of the mechanisms involved in the activation of the rat insulin promoter within pancreas cancer cells 2) obtain the preclinical data needed for a clinical trial which will combine surgery and systemic RIP-TK liposomal gene therapy, and 3) to determine whether rat insulin promoter-thymidine kinase will affect mouse and human islets both invitroand invivo. We hope this strategy will ultimately lead to a more effective treatment for patients with pancreatic cancer using surgery to resect the primary cancer and systemic pancreatic cancer-specific gene therapy to ablate the micrometastases.